The presence of the pumpkinseed sunfish, considered an invasive exotic species, was confirmed in Lac à l’Eau Claire, in the ZEC Rivière-aux-Rats, says Anne-Marie Bouchard, wildlife biologist at the direction of the wildlife management in Saguenay-Lac-Saint-Jean.
“The most plausible theory is that of a voluntary introduction into the body of water,” she confirms. It seems that people wanted to introduce the species for a reason that is currently unknown, she adds.
“I would never have thought that there were people cave enough to introduce a fish like that into a lake in the ZEC Rivière-aux-Rats,” says Marc Archer, disappointed to learn that the presence of sunfish -soleil was confirmed by the Ministry of the Environment, the Fight against Climate Change, Wildlife and Parks (MELCCFP).
A first specimen was caught in 2021 in the Ha! Ha!. (Sébastien Roy/Archives)
“The introduction of a new species can transform an entire ecosystem,” he laments. According to the latter, such an introduction is a much more serious crime than poaching a moose, because it endangers entire populations of fish.
In other words, this introduction is like permanent biological pollution. “The wildlife protection department must investigate this to find those guilty,” adds Mr. Archer, hoping for a hefty fine, commensurate with the damage caused to the ecosystem.
A specimen and environmental DNA
“A vacationer first mentioned having captured a specimen measuring more than 15 cm at the end of summer,” explains Anne-Marie Bouchard. Fishing efforts were then made by the ministry, but without success. Environmental DNA testing, however, confirmed the presence of the pumpkinseed. “We had several positive results, with a high concentration of environmental DNA near the outlet of Lake Eau Claire,” notes Anne-Marie Bouchard.
The species should therefore be found in Rat Lake fairly soon, if it has not already done so, before moving into Rat River. “We have no power to limit its spread,” she said.
It is difficult to predict what damage the species will cause and the MELCCFP will monitor the spread to document impacts on the ecosystem.
-The pumpkinseed is a small fish measuring between 10 and 15 centimeters, from the centrarchidae and bass family.
“It is an extremely resilient fish because it reproduces on any substrate,” maintains the biologist. It protects its nest, its eggs and the young, which makes it a very prolific species, unlike all our native species which do not have such an aggressive reproductive strategy, she adds.
Once established in an environment, the pumpkinseed will compete with other species for food and habitat. As it feeds on insects and small fish, it can significantly harm any native species that are already there, such as walleye, landlocked salmon, brook trout and smelt.
“We are very worried about the impacts that the introduction of this species into the ecosystem will have,” notes Anne-Marie Bouchard, who adds that the pumpkinseed could affect the quality of fishing in the sector.
It is difficult to predict how long it will take before this harmful fish reaches Lake Saint-Jean, but no obstacle now prevents the species from getting there.
“Putting a fish in a lake may seem trivial, but it can disrupt an entire ecosystem for millennia,” notes the biologist, who believes in raising awareness to make the population aware of the dangers of invasive exotic species.
The ministry would like to point out that it is prohibited to keep this species in captivity and transfer fish from one watercourse to another, since these practices can harm ecosystems and compromise the quality of fishing in certain rivers. of water.
Already present in Saguenay
It is due to human intervention that this fish has established itself in the Saguenay River. A first specimen was caught in 2021 in the Ha! Ha!. Today, its range extends to the bridges of the Petite Décharge and Grande Décharge rivers in Alma.
